1. Field of the Invention
The present invention relates to a method and jig structure for positioning bare dice, especially to a method and jig structure for placing and positioning bare dice to expediate the bare dice manufacturing process.
2. Description of Related Art
During encapsulation processes in electronics industry, bare dice are generally vacuum-grabbed and moved onto circuit boards via suckers for the following treatment.
Please refer to FIG. 1 and FIG. 2 in turn, which illustrate a conventional method for positioning bare dice. In the conventional method 1, first provide a tray 1a with a plurality of positioning grooves 11a which are arranged in an array form (FIG. 1 and FIG. 2 only illustrate a single positioning groove, but it is easy to imagine a 2×2, 4×4, or 9×9 array. The number of array shown is for illustrative purpose only).
Then place a bare dice 2a in the positioning groove 11a, wherein the depth of the positioning groove 11a is greater than the height of the bare dice 2a. 
Further, use a sucker 3a to grab bare dice 2a and move it onto a charge coupled device (CCD) 4a, and determine bare dice 2a's center position via image recognition for accurate location.
Having bare dice 2a's center position located, sucker 3a can move bare dice 2a to a predetermined position on a circuit board 6a (as shown in FIG. 4) for bonding operation.
Please refer to FIG. 1 and FIG. 3 illustrating conventional method 2 for positioning bare dice. Similar to conventional method 1, the present method 2 also starts by providing tray 1a with positioning grooves 11.
Then bare dice 2a is placed in positioning groove 11a, wherein the depth of the positioning groove 11a is greater than the height of the bare dice 2a. 
Next, use the sucker 3a to grab bare dice 2a and move it onto an equipment platform which includes a positioning wall 51a and a push rod 52a. A positioning wall's corner 511a defines a positioning point for equipment platform.
The push rod 52a pushes bare dice 2a to abut against the positioning point 511a to attain the position defined by the positioning point and equipment platform.
Accordingly, bare dice 2a can be located at this defined position and can be drawn upwards for transfer to a predetermined position on circuit board 6a (as shown in FIG. 4) via sucker 3a for bonding operation.
However, misaligned bare dice stack appears in conventional methods. Bare dice with a complex geometric shape may not be properly recognized and located by charge coupled device 4a and the push rod 52a cannot evenly push the bare dice with complicated shape to abut against equipment platform's positioning point 511a correctly. So the two described above methods cannot be applied for positioning this kind of bare dice.
Furthermore, conventional methods for positioning bare dice have the shortcomings as follows:
1. Conventional positioning methods have too many steps which prolong working cycle, and positioning devices, such as image reorganization and locating hardware, are expensive and inconvenient to maintain;
2. Conventional positioning methods can only be used for positioning bare dice with simple shapes and cannot position bare dice with complex shapes, which reduces the versatility and flexibility of positioning devices.
Clearly, there is a need to provide a method for positioning bare dice which can effectively simplify positioning process to shorten work cycle and can be suitable for both simple shaped bare dice and complex shaped bare dice.
Hence, the inventors of the present invention believe that the shortcomings described above can and should be improved and finally suggest the present invention which is of a reasonable design and is an effective improvement.